Drafting instrument



SeptQY9, 1958 s. F. MASSARI 2,850,804

DRAFTING INSTRUMENT Filed Jan. s, 1956 llo IIIJLIIIIIIIIII us he JNVENTOR.

STANLEY F. MASSARI F'IG.3

ATTORNEY 2,850,804 DRAFTING INSTRUMENT Stanley F. Massari, Stamford, Conn.

Application January 3, 1956, Serial No. 557,009

3 Claims. (Cl. 33-26) This invention relates to an improvement in drafting instruments and more particularly to an improvement in drafting instruments to provide a universal instrument that will handle most, if not all, of the functions of the many separate instruments that are now required.

The usual technical draftsman today who is called on to turn out engineering drawings uses a minimum of about thirteen instruments. These include the usual array of triangles, scales, templates and other auxiliaries. It is quite obvious that these present a cluttered working arrangement and result in slow production. In addition, to use them for the varied jobs that are presented, many on-the-spot calculations must be made, particularly where angles are involved. It is a particularly slow and diflicult procedure to develop one angle or series of angles from a first angle and much time is consumed in the procedure.

Another difliculty is presented in the use of templates. There are many special shapes or symbols to be used in varying types of drawings (architectural, electrical, etc.) and the correct juxtapositioning of these templates with respect to the remainder of the drawing presents a problem and a source of delay.

It is therefore an object of this invention to provide a universal drafting instrument to replace to an extent the many different instruments now in use. It is an object to provide a universal instrument that will have interchangeable templates formed as an integral part thereof. It is a further object to provide an instrument that will simplify the layout of angled lines emanating from angled lines. Yet another object is to provide a universal triangle. These and other objects will be developed as this specification proceeds.

In summary, this invention accomplishes the above objects by providing a unitary device comprising an interchangeable template formed with at least one straight side and one 180 arcuate side, an arm pivoted from the center of the said arc, the pivoted arm having an arc side on one end thereof with graduated angles marked on the arc, and a second arm pivoted from the center of the second arc.

A preferred embodiment of this invention is shown in the accompanying drawings in which:

Figure 1 is a front elevation of the instrument.

Figure 2 is a side elevation of the instrument.

Figure 3 is a section showing the locking arrangement.

More particularly in the drawings, the universal instrument comprises interchangeable template 10, usually of transparent or translucent material. The template shown in Figure 1 has a series of holes 11 and 11a and a series of ruled scales such as 13. It has at least one straight side 12. It also has at least one curved or arcuate side 30 which is shown with graduations 14 and 14a making at least a 180 arc, the center of the arc comprising pivot 3. The pivot 3 is positioned a short distance above the straight side 12, so that the arcuate side 30 extends from a point on an imaginary line parallel with the straight side 12 on one side to a point Where it contacts that same imaginary line on the other side. The remaining portion of the side 30 is straight from the termination of the arc to its point where it contacts the side 12. In the template shown, the pivot 3 is a threaded shaft on which is mounted a nut 15. Attached to the shaft 3 and pivoted on it is arm 16. This arm may turn through any angle of the arc 30'and may be locked in place at any desired angle by tightening the nut 15. If

tates Patent ire it is locked at a 90 or angle with the straight edge,

.it will function much like the usual triangle or set of triangles or it may be locked at any other angle and be more universally useful. The arm 16 is marked With a scale 17 and has pencil guiding holes 18. The holes 18 may be used to circumscribe an arc of any distance from the template, or they may be used to draw a straight line parallel to the straight edge 12 of the template 10 by moving the template along a straight edge. The template is easily interchanged with another in case special shapes are desired.

At the opposite end of arm 16 is located a second template 19, again presenting at least one curved edge with graduations 20 preferably going through a 180 arc. At the center of the are of this second template is the second pivot 21 on which turns arm 22 which may also be locked in place at any desired angle. This arrangement provides an important advantage in that the second angle may be quickly located and used, without calculation, by the appropriate setting of both arms. It further provides an extension of arm 16, if more length is needed, by being locked at the 90 position. The holes 23 in the second arm permit drawing of arcs about the pivot 21. The radius of the curved portion of the second template 19 is equal to the distance from the center of pivot 3 to edge 12 of template 10, so that when the tip of the template 19 is placed on a line running along straight edge 12, each side of arm 16 will be parallel with edge 12 and thus a series of parallel lines (such as section lines) may be drawn parallel to straight edge 12.

Whereas a particular preferred embodiment has been described and shown herein, the scope of this invention should be determined by the appended claims and their equivalents.

I claim: 1

l. A universal drafting instrument adapted to draw parallel lines which comprises a template having a first straight edge and a curved edge described an arc, with a pivot at its center, the pivot being displaced a distance from the straight edge, an arm pivoted adjacent one end of its centerline at the said center with an edge on either side, a second template integrally formed on the opposite end of the arm, having a base with a straight edge extending perpendicular to the arm, the end of the base being the same distance from the centerline of the arm as the said pivot is from the said first straight edge so that when the edge of said second template is placed on a line running through the said first straight edge, the edges of the arm will be parallel with the said first straight edge, the second template having also a curved edge describing an arc intersecting the base with a pivot at its center and a second arm movably mounted on the pivot.

2. An instrument according to claim 1 in which the movably mounted arms are provided with spaced holes.

3. An instrument according to claim 1, in which both movable arms are thin in section from the pivot to the edge of the arc of each template and of sufficient thickness in section for the remainder of the arms extending beyondthe template so that the bottom of each arm lies in the same plane as the bottom of each template.

References Cited in the file of this patent UNITED STATES PATENTS Germany June 16, 1923 

